Chemistry is one of the chemicals, ionic compounds where the United ionic bonds ions in the structure of the formula of metal cations in general, positive ion and a polyatomic anion is the negatively charged

NaCl sodium chloride
NaI Sodium iodide
NaBr sodium bromide
KCl Potassium chloride
KI potassium iodide
KBr potassium bromide
There are many ionic compounds. but for such an open question you can take any combination of a group 1 element and combine it with any group 7

I. Compounds of great ionic character

Two types of compounds fall into this category: 1. those consisting of a metal combined with a nonmetal (e.g. NaCl, Ag 2S, PbO) and 2. compounds containing polyatomic ions, except for the oxoacids (e.g. CaSO4, NH4NO3, KCN, but excluding H2SO4, HNO3 etc.). For the sake of naming compounds, they will be classified as ionic compounds in this tutorial.

To name an ionic compound, one should name the cation first, then, name the anion (with the word 'ion' omitted). It is not necessary to indicate the number of cations and anions in the compound because it is understood that the total positive charges carried by the cations must equal the total negative charges carried by the anions. A few examples are listed below:

Some ionic compounds incorporate water molecules in their structure. These compounds are called hydrates. To name the hydrates, the number of waters of hydration is indicated by a Greek prefix following the name of the compound. For example, CuSO4�5H2O is called copper(II) sulfate pentahydrate.

Since the number of cations and anions in a molecule is not specified in the name of an ionic compound, to figure out the molecular formula from the name sometimes is not straightforward. The following examples show how this can be achieved in a systematic matter:

Example 1: Give the molecular formula of aluminum sulfide.Solution:i) Since aluminum is a metal and sulfur is a nonmetal, this compound is classified as an ionic compound.ii) The cation, aluminum ion, is: Al3+ (if you forget the charge of the aluminum ion, look up the position of Al in the periodic chart).iii) The anion, sulfide, is: S2- (the –ide suffix indicates that it is a simple anion)iv) How many Al3+ should combine with the appropriate number of S2- such that the molecule carries no net charge? Al2O3 is the answer.Example 2: Give the molecular formula of vanadium(III) phosphate.Solution:i) You may not recognize that vanadium is a metal. However, the suffix –ate in the word 'phosphate' is the hint of an oxoanion, a polyatomic ion. You know that this compound is classified as an ionic compound.ii) The cation, vanadium(III) = V3+iii) The anion, phosphate = PO43+iv) How many V3+ should combine with the appropriate number of PO43- such that the molecule carries no net charge? VPO4 is the answer.Example 3: Give the molecular formula of ammonium sulfate.Solution:i) Both ammonium and sulfate are polyatomic ions, again, this compound is classified as an ionic compound.ii) The cation is ammonium ion = NH4+iii) The anion is sulfate ion = SO42-iv) The molecular formula of the compound is (NH4)2SO4, because it takes two groups of NH4+ to combine with one SO42- to give a molecule that carries no charge.